38 Aluminum - ISO G2 (Parker)
This is the lightest pen, good for long periods of use. Even weight distribution with a very smooth finish on the aluminum tube with slight texture from the machining lines. Has a shockingly light feel and is great to write with. This pen feels lightweight but is definitely very sturdy. Aluminum will weather against harder materials you can keep it fresh or let it wear.
Twist mechanism with triple start screw thread is super simple and reliable. Carbide drill makes the hole in the tip at very precise tolerance of 25 micron. Comes with a very smooth writing Parker style Schmidt P9000 EasyFlow. I pay very close attention to the tolerances and surface finishes. 5-1/4" (133mm) long and 0.36" (9.1mm) in diameter. 34g (1.2 oz) in weight.